Laser microdissection and mass spectrometry–based proteomics aids the diagnosis and typing of renal amyloidosis

Abstract

Accurate diagnosis and typing of renal amyloidosis is critical for prognosis, genetic counseling, and treatment. Laser microdissection and mass spectrometry are emerging techniques for the analysis and diagnosis of many renal diseases. Here we present the results of laser microdissection and mass spectrometry performed on 127 cases of renal amyloidosis during 2008–2010. We found the following proteins in the amyloid deposits: immunoglobulin light and heavy chains, secondary reactive serum amyloid A protein, leukocyte cell–derived chemotaxin-2, fibrinogen-α chain, transthyretin, apolipoprotein A-I and A-IV, gelsolin, and β-2 microglobulin. Thus, laser microdissection of affected areas within the kidney followed by mass spectrometry provides a direct test of the composition of the deposit and forms a useful ancillary technique for the accurate diagnosis and typing of renal amyloidosis in a single procedure.

Biochemical markers in early diagnosis and management of systemic amyloidoses

“…Moreover, the novel proteomic-based analyses of affected tissues have identified sets of tissue-resident (including extracellular matrix components, species involved in protein folding, and proteins implicated in energetic metabolism) and amyloid-associated proteins, whose representation changes in the presence of amyloid deposits [50][51][52]. If validated, these proteins, as single analytes or in combination, could represent novel, sensitive markers of amyloid deposition and indicators of amyloid-associated damage.…”

Leukocyte Cell–Derived Chemotaxin 2–Associated Amyloidosis

“…Typing amyloid deposits by LC/MS-based proteomics is currently the best tool to diagnose ALECT2 amyloidosis and other forms of amyloidosis because of its high sensitivity and specificity and because it is a single test that can detect the culprit protein in contrast to IHC typing of amyloidosis, which requires staining for multiple antibodies using several tissue sections (6,50,51). LECT2 protein has many lysine and arginine residues and therefore, can readily be digested by trypsin into peptides, and the amino acid sequence of the peptides can be determined by LC/MS.…”

Optimal conditions and the advantages of using laser microdissection and liquid chromatography tandem mass spectrometry for diagnosing renal amyloidosis

“…Therefore, LCMS/MS can identify a protein with high specificity and sensitivity. As a result, this new technique has been used to accurately diagnose the type of renal amyloidosis [5,6]. This study attempted to determine the optimal conditions required for LCMS/MS sample analyses.…”

“…Moreover, a higher number also demonstrates a higher confidence in the protein identification. It should be noted that when using the LCMS/MS and Scaffold database, a minimum of 4 mass spectra must be found in the samples to demonstrate any significant amyloid deposition [5,6].…”

“…Based on these issues, proteomic methods have recently been utilized to assess amyloid proteins. Sethi et al [5,6] demonstrated that proteomic methods can detect amyloid proteins using renal biopsy tissue samples. With this method, renal tissues with Congo Red-positive staining were dissected using a laser microdissection (LMD) technique for renal biopsy samples.…”